Systematic Procedures for Formulation Design of Drug-Loaded Solid Lipid Microparticles: Selection of Carrier Material and Stabilizer

Abstract

A systematic procedure is presented for selecting the carrier material and stabilizer for drug-loaded solid lipid microparticles (SLMs). Heuristics criteria as well as investigation methods are proposed. The proposed procedure is based on the summaries of the authors’ investigation and the accumulated heuristics derived from the available literature works. The physical properties of carrier materials, drug distribution in the carrier matrix, the compatibility between drugs and carrier materials, and the crystal structures of carrier matrices are taken into account in the selection of the carrier materials. In stabilizer selection, the coverage of stabilizer molecules on particle surfaces and the electrostatic repulsion and steric repulsion of stabilizers should be considered. The presented heuristics and criteria are to assist with decision making in new SLM development. This is demonstrated with an application case, in which a clozapine-loaded SLM formulation is designed, to illustrate the selection of carrier materials and stabilizers. Experiments and testing have confirmed the effectiveness of the proposed procedure and heuristics.